text: SH2 domains, and other binding domains, have been used in protein engineering to create protein assemblies. Protein assemblies are formed when several proteins bind to one another to create a larger structure (called a supramolecular assembly). Using molecular biology techniques, fusion proteins of specific enzymes and SH2 domains have been created, which can bind to each other to form protein assemblies. 
  Since SH2 domains require phosphorylation in order for binding to occur, the use of kinase and phosphatase enzymes gives researchers control over whether protein assemblies will form or not. High affinity engineered SH2 domains have been developed and utilized for protein assembly applications.
  The goal of most protein assembly formation is to increase the efficiency of metabolic pathways via enzymatic co-localization.  Other applications of SH2 domain mediated protein assemblies have been in the formation of high density fractal-like structures, which have extensive molecular trapping properties.